I need some help PING...
"Logged in, are you?"
somebody had to say it
When you boot, do you see anything or is it blank even during boot?
But seriesly, look at the keyboard for a FN-combination of keystrokes that might've turned off your laptop monitor, while leaving the external VGA port active.
It's typically fn+F5, but your keyboard may vary.
On some models there is a key sequence - shift-F5 on mine - that deactivates the laptop screen in favor of the external video. Check your manual for what that might be on your unit. Hit it a few times.
With the external monitor attached, you might try getting into Device Manager (Control Panel/System/Hardware tab) and looking for signs of failure under the "Display adapters" icon and the one labeled "System devices".
Then it's the shop, I'm afraid. Good luck and let me know if you get any more information.
FYI - The new Intel-based Mac computers can run Windows XP.
Another thing to check:
Sometimes the little switch, near the hinge that turns the display (backlight) off when you close the lid can get stuck or dirty. Try jiggling it (this is actually a direct quote from a Toshiba technical paper). Likewise sometimes the 'power saving' settings can get confused and turn off the backlight.
When I googled the backlight issue recently I happened upon a very long techinical forum thread that discussed these fixes and the whole process of taking your display apart and replacing the bulb or inverter.
Tech & Tech support pings?
Still no joy on the RAM (though I'm sending the 512 back to Kingston)...
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus